GB2268966A - A door latching arrangement. - Google Patents

Abstract

A motor vehicle door latch arrangement has a striker plate 26 mounted on the door 10 and a latch mechanism 30 mounted in the adjacent door frame 14. Operation of the latch mechanism is through interior and exterior door handles 18 and 20 which operate levers 50, 54 at the door edge. The levers act on operating fingers 96, 98 on the latch mechanism. <IMAGE>

Description

A Door Latching Arrangement This invention relates to a door latching arrangement for use on a motor vehicle.

Conventional door systems require a latch mechanism which is mounted on the door and a striker plate which is mounted on the door frame. The striker plate is generally static, and the moving parts of the latch are included in the latch mechanism and are thus contained in the vehicle door.

Additionally the vehicle door latch conventionally has an interior operating handle mounted on the door and an exterior operating handle also mounted on the door.

Operation of these. handles moves parts of the latch mechanism to open the latch and also, possibly, to lock/unlock the mechanism.

According to the present invention there is provided a latch arrangement for a vehicle door, the arrangement comprising a latch mechanism and a striker plate with the striker plate being mounted on the door and the latch mechanism being mounted on the door frame.

By mounting the latch mechanism on the door frame it is possible to house the mechanism within the fixed vehicle bodywork and thus to make it more secure against unauthorised tampering. Furthermore electrical connections to the latch mechanism, for example central locking motors can all be mounted on the fixed vehicle bodywork rather than in the door shell.

As a result of the mounting of the striker plate rather than the latch mechanism Qn the door, the package requirements in respect of the door are reduced. This can increase the available interior space in the door which, for example, can allow a larger glass area to be fitted because there will be more space for the glass to be housed inside the door.

The arrangement preferably includes both interior and exterior door handles connected to operating means by which either handle can operate the latch mechanism. The door handles are preferably connected to a lever or levers projecting from the edge of the door adjacent to the latch mechanism, and the latch mechanism preferably has a corresponding finger or fingers which projects from the door frame in a manner such that they can be engaged by the levers to produce an operating movement of the latch mechanism.

The interior and exterior door handles are preferably connected to the lever or levers by means of cables.

The latch mechanism preferably also includes a locking mechanism which may be operated without a mechanical key.

It is anticipated that the normal unlocking action will be undertaken by a remote, non-contact actuator such as an infra-red actuator. In this event there will be no need for key actuation, but an emergency key operation for the lock maybe provided in the door frame, with the key being inserted into a key cylinder through an access channel between a doors and the frame. Because the key access will only be used in emergencies, the location of the key aperture in the key cylinder can be concealed so that it is substantially protected from thieves.

The invention will now be further described, by way of example, with reference to the accompanied diagrammatic drawings, in which: Figure 1 is a schematic side view of a vehicle showing two vehicle doors and associated bodywork in accordance with the invention; Figure 2 is a section through the vehicle B-pillar and showing the edges of the adjacent doors; Figure 3 is a view on the edge of the door which carries a striker plate; Figure 4 is a corresponding view on the corresponding face of a latch mechanism; Figure 5 is an elevation view showing the edge of the door and the door frame in the relative positions which they adopt when the door is closed; and Figure 6 illustrates location and operation of an emergency key release.

Figure 1 shows a front door 10 and rear door 12 on one side of a car. A door frame member 14, commonly called a Bpillar, forms part of the fixed vehicle bodywork and provides a rear frame edge for the front door 10 and a front frame edge for the rear door 12. The rear frame edge for the rear door 12 is formed by another frame member 16, the C-pillar.

The front door 10 has an interior handle 18 and an exterior handle 20 and both of these handles are connected by Bowden operating cables 22, 24 to a striker plate unit 26 mounted on the edge of the door. The striker plate unit carries a striker pin 28 which engages with a latch mechanism generally indicated at 30 and mounted within the B-pillar 14. Similar components on the rear door are indicated by the same reference numerals with the edition of a suffix 'a1.

In order to obtain access to the latch mechanism 30, 30a there are cut-outs 32, 32a in respectively the B-pillar 14 and the C-pillar 16. These cut-outs are normally concealed either by the door itself or by other trim panels or bodywork, when the vehicle is fully assembled.

Figure 2 shows how the doors 10, 12 can overlap one another in the area of the B-pillar 14 and can therefore conceal the B-pillar from view, on the outside of the vehicle. The Bpillar can also support a key cylinder 34 for emergency locking/unlocking as will be described later with reference to Figure 6.

Figure 3 shows details of the striker plate unit 26. The unit has a backing plate 36 which is mounted inside the door panel and which supports two levers 38 and 40 on pivots 42, 44 respectively. The lever 38 is spring-loaded in the anticlockwise direction by a spring (not shown) and can be pulled in the opposite direction against the spring force by the centre wire 46 of the Bowden cable 22 which is connected to the interior door handle. In the same way the lever 40 is spring biased in an anti-clockwise direction and can be moved in an opposite direction by the centre wire 48 of the Bowden cable 24 which is connected to the exterior door handle. The lever 38 has a horizontally extending surface 50 which passes through a cut-out 52 in the plate 36 so that the edges of the cut-out define the allowable movement of the lever.In the same way the lever 40 has a horizontal surface 54 which moves in a cut-out 56.

A striker pin 58 is supported in a stirrup 60 which is mounted on the outside of the door edge panel and is secured through the door edge panel to the backing plate 36.

Figure 5 shows the components of Figure 3 in side elevation and in particular the fastening screws 62 which secure the striker pin stirrup 60 to the backing plate 36 can be clearly seen, along with the horizontally extending surfaces 50, 54 of the levers 38, 40. In Figure 5 the part of the door inner panel which forms the door edge is indicated at 64.

The latch mechanism is shown in Figures 4 and 5 and is mounted within a casing 66 which has in its front face an access track 68 for the striker pin 58. A rotor 70 is pivoted at 72. In the position shown in Figure 4, the rotor 70 is held in a position where it will retain the striker pin 58 in a latched position (at this time the striker pin 58 will sit within the space designated 74), and the rotor is held in this, latched, position by a pawl 76 which engages with the rotor and prevents anti-clockwise movement.

The pawl 76 has a tooth 78 engaging with the rotor, and is mounted on a pivot axis at 80.

A lock lever 82 extends from top to bottom of the mechanism 30 and has an aperture 84 which receives a pin 86 on the pawl 76. When the lock lever 82 is lifted, the pin 86 and the pawl 76 will be lifted so that the rotor 70 is free and can rotate the striker pin 58 when the door is pulled open.

The latch mechanism has a top pivoted link 88 and a bottom pivoted link 90, these links being pivoted at 92 and 94 respectively. The left hand ends of these links carry fingers 96 and 98 which extend laterally from the housing 66 to register with the horizontal surfaces 50, 54 of the striker plate levers 38, 40 (see Figure 5).

In Figure 4 the lock lever 82 is shown in bold lines in the "door unlocked1?. In this position when either one of the fingers 96 or 98 is lifted by operation of either the cable 22 or the cable 24 (the interior handle or the exterior handle) then the plate 82 will be lifted, the pawl 76 will be lifted and the door will be unlatched.

Figure 4 also indicates the "door locked" condition which is shown in dotted lines. When the lock lever 82 is moved into its "door locked" position it pivots anti-clockwise about the pin 86 of the pawl 76 and then the fingers 96, 98 move into enlarged apertures in the lock lever. When either of the fingers is lifted by operation of the interior handle or the exterior handle, the fingers have a lost motion in the apertures 100, 102 and the door is not unlatched. Movement of the lock lever 82 between these two positions is carried out by a motor 104 which acts on a pin 106 in a slot 108 of the lever 82.

The key cylinder 34 has at its inside end a radial arm 110 which ends in a spigot 112 engaging between two lugs 114 on the lock lever 82. By turning the key in key cylinder the arm 110 must be able to rotate the lock lever 82 about the axis of the pin 86 to move the plate 82 from the "door locked" to the "door unlocked position and to do this the key action is able to overcome the resistance of a clutch associated with the motor 104.

Figure 6 shows how a key 116 for the lock cylinder 34 can be inserted in the cylinder by passing behind the rear edge 118 of the front door 10 and through a notch 120 in the edge 122 of the rear door 12. As a result of this arrangement, the key cylinder 34 is substantially sealed and is protected from attack.

In use, operation of the latching mechanism appears to the user to be the same as a conventional system where the latch mechanism itself is mounted on the door. When the inside of the door handle is operated, the lever 38 is lifted and this lifts the finger 96, the lock lever 82 and the pawl 76. The door is then free to open. When the door handle is released, the various springs will return the associated components to the position shown in Figures 3 and 4 (except that the rotor 70 will be rotated anti-clockwise from its Figure 4 position, to accept the striker pin 58 as the door is closed). The door can then be slammed shut whereupon it will become latched.

If instead the exterior door handle is operated, exactly the same sequence of events will take place.

To lock the door once it has been latched will normally be done by an external central locking system activated by a system which forms no part of this invention but which will act on the motor 104 to drive the lock lever 82 from its position shown in bold lines in Figure 4 to the position shown in dotted lines. Under some locking strategies, there may be three positions of the lever 82, namely unlocked, locked and double locked. Only two positions are shown in Figure 4. However when three positions are provided, in the unlocked position both interior and exterior handles can lift the pawl 76; in the locked position only the interior handle can lift the pawl and in the double-locked condition neither handle can lift the pawl.

If for any reason the motor 104 cannot be operated then the door can still be opened by inserting the emergency key 116 into the cylinder 34 through the narrow access notch 120.

This will have the same effect of rotating the lock lever 82 from the locked position (dotted lines) to the unlocked position (full lines).

Conventional door latches mounted in vehicle doors are vulnerable to attack through the clearances provided for the moving glass of the windows and through externally mounted lock components. The design described here avoids this vulnerability by positioning the latch mechanism within the B-pillar. Furthermore because the emergency lock cylinder 34 is located below the external body surface, a long thin key is required to operate it and the location of the cylinder and the size of the access notch 120 would hinder any attempt to apply substantial torque to the cylinder to break it. Because of the use of flexible cables 22, 24 to connect the striker plate with the handles, any interference with these cables will not of itself cause the latch mechanism to operate. It is necessary to separately act on the central wire of the cable in order to operate the latch mechanism.

Furthermore the increased space inside the door which is afforded by locating only the striker plate assembly in this position allows more space for a glass run channel. Figures 3 and 5 indicate with dotted lines 124 the possible location of a glass run channel, and the small channel-to-door dimension 126 (Figure 5) leads to the possibility of thinner visible B-pillars than could be achieved with prior constructions.

Claims (7)

Claims

1. A latch arrangement for a vehicle door, the arrangement comprising a latch mechanism and a striker plate with the striker plate being mounted on the door and the latch mechanism being mounted on the door frame.

2. A latch arrangement as claimed in Claim 1, wherein interior and exterior door handles are mounted on the door and operating means are provided by which either of the handles can operate the latch mechanism.

3. A latch arrangement as claimed in Claim 2, wherein the door handles are connected to a lever or levers projecting from the edge of the door adjacent to the latch mechanism, and wherein the latch mechanism has a corresponding finger or fingers which projects from the door frame in a manner such that the fingers can be engaged by the levers to produce an operating movement of the latch mechanism.

4. A latch arrangement as claimed in Claim 3, wherein the interior and exterior door handles are connected to the lever or levers by means of cables.

5. A latch arrangement as claimed in any preceding claim, wherein the latch mechanism includes a locking mechanism, means for keyless operation of the locking mechanism and an emergency key operated release for the locking mechanism provided in the door frame, with the key being inserted into a key cylinder through an access channel between a door and the door frame.

6. A latch arrangement as claimed in Claim 5, wherein the key cylinder is concealed so that it is substantially protected from thieves.

7. A latch arrangement for a vehicle door, substantially as herein described with reference to the accompanying drawings.